John Liu’s hard-fought victory in the Democratic race for comptroller could cost him an astounding $588,000 in fines — the most violations ever slapped on a candidate for plastering the city with illegal posters.

According to figures compiled by the Sanitation Department, Liu’s campaign has received 7,840 violations so far.

Each carries a penalty of $75, meaning he’ll have to fork over more than $500,000 unless the penalties are reduced at the Environmental Control Board.

The board hasn’t shown much willingness to bend on this issue.

Last week, officials from the Chamber of Commerce, Kiwanis and Lions Club of Maspeth, Queens, complained the ECB wouldn’t give them a break after Boy Scouts attached 32 posters to light poles advertising a street fair in June 2008.

A hearing officer decided each organization was equally guilty, and imposed fines totaling $7,200, or half the take from the entire street fair. An appeal failed.

Juanita Scarlett, a Liu spokeswoman, said she couldn’t comment because the campaign knows of no violations.

“We never received notification about fines or penalties — not one,” she said.